SPACE COMMAND PLANS Y2K TESTS ON GPS
Federal Computer Week
The U.S. Space Command plans to conduct another series of Year 2000 tests on the
Global Positioning System this month.
The Space Command plans to conduct Year 2000 tests on Space Vehicle 43 in the GPS constellation June 22, June 25-26, June 28 and July 1. The tests, which the command at Peterson Air Force Base, Colo., has yet to officially announce, will involve advancing the system clock in the satellite to Dec. 31, 1999. Other tests will include advancing the clock to Feb. 28, 2000, to test that the satellites will work on Feb. 29 and March 1.
In addition, the Space Command on June 28 will test the GPS' "end-of-week rollover," which occurs about every 20 years. More precisely, every 1,023 weeks, the GPS clock starts over at 0000 weeks. GPS system time commenced Jan. 6, 1980 -- when the first satellite in the constellation began operation -- and was programmed to roll over after 1,023 weeks. Rollover will occur at midnight between Aug. 21 and Aug. 22, 1999.
One specialized group of users has started to brace itself for the possibility of disastrous results from the tests. In April, the Space Command experienced problems when it conducted a test on one of the 24 satellites in the GPS constellation. Scientific institutions that belong to the International GPS Service (IGS), which maintains a worldwide network of 200 GPS receivers that measure tectonic plate movements and provide centimeter-level accuracy to surveyors, reported widespread problems during the April tests. "A disturbingly large number of receivers in the global network had problems,'' one user told FCW.
The problems occurred in flash cards used to store data received from the satellites for post-processing and analysis of satellite data. "Users could not get the data out," the user said, "and we experienced a half-day outage" as a result of the tests.
The manufacturer of the receiver used extensively in the IGS network, Allen Osborne Associates Inc., has updated software for all its receivers, according to Scott Osborne, the company's vice president. Osborne said if users in the IGS network experienced problems during the last test, "they have not asked for upgrades...because we have
upgraded 20-year-old receivers."
Osborne said users also may experience problems because they installed their own software in the receivers.
Osborne said his company has spent millions of dollars to ensure the Year 2000 compliance of receivers. He said the users experienced problems in the April tests because the receivers were tracking operational satellites, which were running in real time, as well as the test satellite, which had artificially advanced time. Osborne said
users wanting to test their receivers should isolate the test satellite from the operational satellites.
fcw.com
MORE ON GPS PROBLEM:
Message 9567593
Timing errors due to the lack of synchronization, in fact, can lead to data loss and degradation and eventually to network disruption or even complete failures. Because of the interconnective and interdependent nature of networks, these problems, in turn, could impact other networks and even the Internet.
house.gov
Wonder what impact that would have on these Internet stocks???
Cheryl
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